Chromiferous azo-dyestuffs



Patented Oct. 20; 1931 V UNITED STATES PATENT OFFICE f I HAN SKRZIKAL-LA, OF MAN NHEIM, GERMANY, ASSIGNOR TO GENERAL ANILIN E WORKS,

INC., OF NEW YORK, N. Y., A CORPORATION OF DELAWARE 1 crmomrnnous.AZO-DYESTUFES No Drawing. Application filedJuly'26, 1930, Serial Noi471,087,'and. in Germany August so, 1929.

The present invention relates to chromiferous azo dyestuffs and processof producing same. I

I have found that valuable chromiferous dyestufls are obtained bytreating the orthohydroxyazo dyestuffs obtainable from diazotizedortho-aminocresol sulphonic acids free from further substituents and1-phenyl-3- methyl-5-pyrazolone in substance with agents I supplyingchromium. The azo dyestufis accordingly correspond to the formula;

stuffs with chromium acetate, formate or fluoride under a refluxcondenser or by heating under pressure. The chroming may also be carriedout with salts of hexavalent'chromium for example by heating thedyestufl's with chromate with or without an addition Q of reducingagents and/0r alkali binding agents. g

The dyestufls so obtained dye wool from acid baths usually red shades.The dyeings thus obtained have an excellent fastness to light, washingand fulling and possess good evenness.

The following example will further illustrate the nature of thisinvention, but the invention is not restricted to this example. 40 Theparts are by weight.

Ewample About 39 parts of the am dyestuffs 0btainable from3-amino-4-cresol-5-sulphonic acid and l-phenyl-3emethyl-5-pyrazolone areboiled in aqueous solution for about 20 hours under a reflux condenseror heated for about 2 hours in an autoclave to 120 C. with'from about 20to 22 parts of a chromium oxide 1 0 to llparts of an 85 per cent formicacid. Thechromium compound obtained is salted out if necessary anddried; Thechromed dyestuffs thus obtained dyes wool very evenly andyields a red shade withexr;

cellent properties of fastness. The chroming may also be carried out inthe presence of I dissolved'salts as for example common salt.

The ortho-hydroxyazo dyestuffs obtainable from diazotized 3aminol-cresol-6-sulphonic acid and 1-phenyl-3-methyl-5-pyrazolone v maybe chromed in an analogous manner. The chromium compound thus obtainedpossesses similar properties tofthose 'hereinbefore described inthisexample. What I claim is 1' 1. As new articles of manufacture; com

plex chromium compounds of am dyestuffs" corresponding to the formulaidyeing wool from acid bathseven red shades. I

2. As a new article of manufacture the com plex chromium compound of theazo'dyestuffs corresponding to the formula:

" N=Nfl(IIIIGH;

on Q= y I dyeing wool even red shades.

. In testimony whereof I have hereunto set my hand.

HANS KRZIKALLA.

